“Although the U.S. military no longer officially uses the M40, they still keep some around. A few found their way to Afghanistan where they were put to use by certain Special Forces units. The Danish and Australian armies, which acquired them from the U.S. decades ago under the Foreign Military Sales (FMS) program, used them extensively during their ground operations there.
“In Libya, the M40 was used primarily in urban warfare, killing tanks and fortified positions. How exactly it found its way into the hands of the rebels there is a bit of a mystery. The M40s showed up in Libya along with thousands of brand new Belgian FN rifles, apparently from Western arsenals. That lead many to suspect they were supplied by Western intelligence. The M40s currently being seen in Syria might be coming either from the same sources that supplied the Libyan rebels or even from the Libyans themselves.
“There is also a strong possibility that these weapons might actually be of Iranian origin. Iran’s state-owned weapons arsenal, the Defense Industry Organization, has been manufacturing what was originally a licensed-version of the M40. Now called the “Anti-Tank Gun 106,” it is being offered on the open market, and are probably being supplied to the Syrian Army, which have since lost them to the rebels.”
The M40, as dated as it is, is a pretty sweet piece of kit. It’s a recoilless rifle, which is different than a traditional cannon or howitzer in that it has no breech and vents gas out the back of the gun to stop its rearward motion. Which of course makes it terrifying.
It’s simple, can be mounted on just about any vehicle, and, well, it’s a 106mm noise-maker. It was originally intended to serve as an anti-tank weapon but it’s clearly a worthwhile all-purpose gun.
Although it was supposed to be retired in 1970, it’s still in some service with U.S. forces to this day.